Since the 1970s, and accelerating
since 1990, the ties between formal marriage and family life have
attenuated. Nearly half of American adults are now unmarried at any
given time, and two of five children are born to unmarried
parents. At the same time, delayed marriage, divorce, remarriage, and
changing gender roles have transformed marriage itself.

Despite
these changes, the federal income tax and the Social Security system
continue to define family based on formal marriage, and our casebooks
teach students
that the economic vulnerability of the married woman is the central
problem of gender in welfare-state design. In this article, I argue that
both joint filing in the income tax and the spousal benefit in Social
Security stand in need of major reform, because
they no longer plausibly foster individual freedom or tailor taxation
and benefits to welfare. Even those who see value in traditional
marriage, I argue, should prefer explicit marriage subsidies to the
arbitrary penalties and bonuses embedded in present
law.